Adjustable seat



(NoMode1.-) r v (1-H, BIGGS & F H. PAIR/CHILD. ADJUSTABLE SEAT.

- No.-47s,s40. Patented July 12 1892.

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WITNESSES INVENTOfiS 2 .41 1 4 5 I W NITED STATES PATENT OFFICE.

CHARLES HENRY BIGGS AND FRANK H. FAIRCHILD, OF DETROIT, MICHIGAN.

- ADJUSTABLE SEAT.

SPECIFICATION forming part Of Letters Patent N0. 478,840, dated Ju1y'12,1892.

Application filed February 3, 1892- V Serial lilo-420,693- (No model.)

T0 at whom it may concern.-

Be it known that we, CHARLES HENRY BIGGS and FRANK H. FAIROHILD, ofDetroit, in the county of Wayne and State of Michigan, have jointlyinvented a new and useful Improvement in Adjustable Seats of Stools orChairs, of which the following is a specification.

In the annexed drawings, making part of this specification, Figure 1 isan elevation, partly in section, of the standard and seat with theconnecting mechanism. Fig. 2 is an elevation showing the lower end ofthe vertical wedge-formed shaft. Fig. 3 is a similar elevation of a cagewhich contains the clamping-rollers. Fig. 4 is a horizontal section ofthe same, showing the rollers and shaft.

A is the pedestal, with three or four legs, the standard B of which ishollow from the top toward the bottom and lined, preferably, with ametallic tube B.

O is a cap placed on top of the tube, formed with a central boss andfastened to the wood by screws or attached in other convenient manner.

In the bottom of the hollow part of the standard is placed a cage D,which may be made of wood, turned to the form shown in Figs. 3 and 4.Recesses are cut at D to contain the rollers E, which turn looselytherein. There are three of these, arranged as shown in Fig. 4, and theyplay loosely in the recesses D,-f0rmed in the cage D. On the extension Dof this cage D there is cut a groove D and a collar F surrounds theextension D while a set-screw F tapped through the col- "lar, enters thegroove D so that the collar,

while free to turn on the cage, cannot be separated therefrom. Thiscollar rests on the shoulder at the base of the extension D A tube G isthreaded at the top and bottom, the latter being received in acorresponding thread in the upper end of the collar F. This tube Gpasses up through a hole in the center of the boss of the cap 0 and isthreaded at the top to receive the boss II on the bottom of the seat H.A rod I is attached to a lever K, which is pivoted at K'tothe seatbetween two of the transverse bars and extends down through the interiorof the tube G and the cage D beyond the wheels E, its lower end beingtapered to form a preferably threesided wedge I, which is so adjusted asto proj ect through the space between the wheelsE E and rest against allthree of them.

L is a spring attached to the bottom of the seat, the tension of whichpresses downwardly upon'the lever K.

The operation of the mechanism hereinbefore described is as follows: Theseat in Fig. l is shown in its lowest position. The seat 'is connectedby the boss II with the tube G and collar F, which rest upon theshoulder of the cage D, by which it is supported, being free to turnthereon. WVhen it is desired to raise the seat, one hand grasps the edgeso that the fingers may rest on the brass plate K ,fastened to the endof the lever K, the other hand being placed under the seat on theopposite side. The upward strain forces the lever K upward, lifting therod Iand raising the wedge-formed point I, so as to sufiiciently freethe wheels E. When the seatis lifted everything inside of the tube B islifted, with it, being entirely free to move upward. When the seat hasbeen sufficiently raised and is released, the lever K is forced down bythe spring L, and with it the rod I is forced down, so that the wedgedpoint I is driven .into the space between the three rollers E, forcingthem outwardly against the interior surface of the lining B, thusforming a friction-clutch, the resistance of which increases with theincrease of theweight on the seat. Thus the seat is firmly sustained inany position within the range of the'pedestal. When it is desired tolower the seat, the reverse operation is performed. The lever K is againlifted, together with the rod I, and wedge I is drawn from between thewheels E, leaving them free to turn back toward the center of the cageand out of frictional contact with the tube B. The seat is then let downby hand into such position as may be desired, when the release ofthelever and the action of the spring again looks it, as before.

What we claim as our invention, and desire to secure by Letters Patent,is

1. In combination with the hollow standard and adjustable seat, thelever placed under the seat and extending to or nearly to its periphery,the pointed rod attached to the lever, and wheels carried in avertically-adj ustable cage placed within'the standard to form afriction-clutch by the outward pressure of the inclined faces of therod, forcing the wheels against the interior face of the hollow standardto support the seat at any point within the range of its adjustment,substantially as set forth.

2. In combination with the hollow standard and swiveling seat, thewheel-carrying cage D, means for locking the cage in the standard, andcollar F, attached to but free to turn on the cage, the cap 0, and tubeG, attached at one end to the collar and at the other to the seat andintermediately supported by the cap, substantially as set forth.

In combination with the hollow standard and adjustable and swivelingseat, the vertically-adjustable cage D, the seat carrying tube G,resting and free to turn thereon, the lever K, pivoted to the seat, andpointed rod L, attached thereto, and wheels E, placed within a chamberin the cage and capable of being forced outward against the interiorwall of the standard by the inclined portion of the pointed rod,substantially as set forth.

4:- In combination with the hollow standard and adjustable and swivelingseat, the cage D, constructed with an extension D and groove D thewheels E, chambered in the cage, collar F, set-screw F, which engagesthe groove D and permits rotary motion only to the collar in itsrelation to the cage, tube G, to which the seat is attached and whichrests on the collar, the pointed rod I I, the inclined faces of whichforce the wheels outwardly against the wall of the hollow standard, andspring-pressed lever K, pivoted to the seat, substantially as set forth.

In witness whereof we have hereunto subscribed our names in the presenceof two subscribing witnesses.

CHARLES HENRY BIGGS. FRANK II. FAIRCHILT).

\Vitnesses:

R. MASON, M. A. lIowEY.

